1. Field of the Invention
The invention relates to a method of configuring a system comprising a moving screen of the type comprising a roller blind, shutter, garage door, projection screen, or analogous element that is driven by an actuator. Such an actuator generally comprises an electric motor powered under the control of an electronic unit. The electronic unit interacts with a control member that may be fixed, in which case control takes place in a wired mode, or portable, in which case control take place by radio or infrared. Such a control member is sometimes referred to as a “control point”. When control takes place over wires, it is often referred to as a “control box”, whereas when control takes place by radio or infrared, reference is often made to a “remote control”. Thus, actuating a button of the control member causes the actuator to execute an order. One button may cause the actuator to move in one direction, and another button may cause it to move in the opposite direction.
2. Brief Description of the Related Art
For reasons of comfort and/or safety, that type of system enables the opening of the screen to be controlled automatically. It is then necessary to program the stroke of the screen, and in particular its high and low end-of-stroke positions. Some actuators manage screen positioning by an electronic unit counting the number of revolutions performed and/or detecting a threshold motor torque, for example. Under such circumstances, a training stage is needed during which the electronic unit switches over to a mode that enables the parameters of the system to be defined. Those parameters identify the high and/or low end-of-stroke positions.
To switch over to training mode, a first solution consists in varying the power supply to the electronic unit, e.g. switching it off twice in succession within a determined period of time. That solution is not practical if a plurality of actuators share the same power supply and if it is not desired that all of them should switch over to training mode together. It is also known, for the same purpose, to connect a shunt between two phases of the motor for a determined duration. The shunt may be obtained by a special adjustment tool or by physically connecting together two terminals on the electronic card of the control point via a metal component. That solution requires a suitable tool to be used and requires the system to be dismantled in order to make the shunt connection.
In another approach, it is possible to press simultaneously on two of the buttons of the control member, for example the up and the down buttons, or the stop and the programming buttons. In itself, that operation does not cause the screen to move at all. It is then not clear whether the operation has been carried out properly. Furthermore, certain control members do not enable two buttons to be activated simultaneously or do not have a stop button or a program button. This is true in particular when renovating a system in which it is not necessarily desirable to change the control member(s) and/or to rewire the installation.
To solve this problem, WO-A-00/49262 describes a configuration method and system using control members having two buttons: on and off. To cause an electronic unit controlling an actuator to switch over to training mode, a sequence of button presses must be executed, each button needing to be pressed in a determined time. If the sequence is achieved, then the electronic unit switches over to training mode. With such a method and such a system, the order transmitted by a control member is always executed after a time delay in order to verify whether or not the user is beginning a sequence of presses for switching over to training mode. This time delay is undesirable in normal operation. Furthermore, it is not obvious how to tell whether the switchover to training mode had indeed taken place, since no movement results between the successive button presses.
EP-A-0 718 729 discloses causing a roller blind to perform a predetermined movement, such as down a little and then up, after a user has fully executed an operation seeking to cause the blind to switch over into programming mode. It is only after a processor unit has entered programming mode that the above-mentioned movement of the blind takes place, so that while entering a programming order, the user cannot be certain that the order is indeed correct. Furthermore, the panel moving down a little and then up is not necessarily representative of the programming order, which can lead to a certain amount of confusion for the user.